This invention relates to automotive suspensions and more particularly to a jounce bumper assembly for a suspension strut providing a controlled spring rate.
The U.S. Pat. No. 4,681,304 issued July 21, 1987, to M. Hassan and entitled Deflection Jounce Bumper For Strut Suspension discloses a jounce bumper having initially high dampening load displacement resistance. A generally cylindrical shaped elastomeric bumper is provided having a solid upper hub portion encircling the strut piston rod. A lower impact portion of the Hassan bumper has outer and inner concentric wall portions defining an intermediate downwardly opening channel. The wall sections are interconnected by a plurality of integral column-like arcuate bridging segments defining therebetween an axial blind bore. Upon the bumper being impacted the wall sections together with the bridging segments stretch to absorb impact energy thereby achieving the initially high dampening load displacement resistance. The jounce bumper of the '304 patent is expensive to manufacture and has a limited service life.
The U.S. Pat. No. 4,434,977 issued Mar. 6, 1984 to Chiba et al. discloses a strut type suspension for a vehicle. The Chiba et al. patent is an example of a prior art jounce rubber bumper fitted onto the piston rod which functions to dampen and limit the action of the shock absorber during its jounce stroke.